The increasing wide variety of technologies used in the drive train of a vehicle demands of the engine manufacturers a high flexibility in the process chain and an associated reduction in the production costs. Therefore, development is tending toward a modularization of the components and toward an integration of additional functions in the components. In the course of this development there have been designed, for example, camshaft modules in which one or two camshafts are preassembled in a bearing frame as part of the cylinder head or in a covering hood as a complete cylinder head. Such prefabricated camshaft modules need only be placed on the cylinder block when mounting the combustion engine. The only remaining manufacturing step is the mounting of traction means, in particular the toothed belt or the timing chain, on the camshaft wheel.
To ensure that the timing ratio, given by the angular position, between camshafts and crankshafts corresponds to the predetermined degree, attention must be paid when mounting the traction means on the camshaft wheel to the exact angular position of the cams acting on the valves in terms of the two camshafts with respect to the valves on the one hand and with respect to the crankshaft on the other hand. Setting the correct angle between the rotating components involved is time-consuming and negatively influences the manufacturing costs.
In order, in conventional combustion engines, to be able to fix the angular position of the camshafts for mounting, it is known from WO2004/106716 A1 to secure a camshaft with a bolt which is guided through the cylinder head from above and which engages through a bore or a notch in the camshaft and is fixed in the cylinder block. The bolt can also assume the function of a mounting aid when assembling the engine. However, the design measures on the camshaft are great and negatively affect the stability of the camshaft. In addition, handling the bolt is uncomfortable insofar as the bore or notch in the camshaft cannot be seen from outside.
DE 10 2007 056 608 A1 discloses a tool which is used only during repairs in order to temporarily fix the position of the camshafts that exists prior to demounting a V-belt or timing chain. This tool engages in the teeth of the toothed wheel and is braced against the engine block by means of a screw. However, this tool only allows a provisional and temporary fixing of the camshafts. The engagement of the tool in the toothed wheel functional surface can also lead to damage or to remaining abrasion on the camshaft wheel.